Package org.apache.druid.query.topn

Class TopNQuery

java.lang.Object

org.apache.druid.query.BaseQuery<Result<TopNResultValue>>

org.apache.druid.query.topn.TopNQuery

All Implemented Interfaces:

Query<Result<TopNResultValue>>

public class TopNQuery
extends BaseQuery<Result<TopNResultValue>>

Field Summary

Fields

Modifier and Type	Field	Description
static final String	TOPN

Fields inherited from class org.apache.druid.query.BaseQuery

QUERY_ID, SQL_QUERY_ID, SUB_QUERY_ID

Fields inherited from interface org.apache.druid.query.Query

DATASOURCE_METADATA, GROUP_BY, SCAN, SEARCH, SEGMENT_METADATA, SELECT, TIME_BOUNDARY, TIMESERIES, UNION_QUERY, WINDOW_OPERATOR

Constructor Summary

Constructors

Constructor	Description
TopNQuery(DataSource dataSource, VirtualColumns virtualColumns, DimensionSpec dimensionSpec, TopNMetricSpec topNMetricSpec, int threshold, QuerySegmentSpec querySegmentSpec, DimFilter dimFilter, Granularity granularity, List<AggregatorFactory> aggregatorSpecs, List<PostAggregator> postAggregatorSpecs, Map<String,Object> context)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
List<AggregatorFactory>	getAggregatorSpecs()
DimFilter	getDimensionsFilter()
DimensionSpec	getDimensionSpec()
DimFilter	getFilter()
List<PostAggregator>	getPostAggregatorSpecs()
Set<String>	getRequiredColumns()	Returns the set of columns that this query will need to access out of its datasource.
RowSignature	getResultRowSignature(RowSignature.Finalization finalization)
int	getThreshold()
TopNMetricSpec	getTopNMetricSpec()
String	getType()
VirtualColumns	getVirtualColumns()
boolean	hasFilters()
int	hashCode()
void	initTopNAlgorithmSelector(TopNAlgorithmSelector selector)
Query<Result<TopNResultValue>>	optimizeForSegment(PerSegmentQueryOptimizationContext optimizationContext)
String	toString()
TopNQuery	withAggregatorSpecs(List<AggregatorFactory> aggregatorSpecs)
Query<Result<TopNResultValue>>	withDataSource(DataSource dataSource)
TopNQuery	withDimensionSpec(DimensionSpec spec)
TopNQuery	withOverriddenContext(Map<String,Object> contextOverrides)
TopNQuery	withPostAggregatorSpecs(List<PostAggregator> postAggs)
TopNQuery	withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec)	Returns a new query, identical to this one, but with a different associated QuerySegmentSpec.
TopNQuery	withThreshold(int threshold)

Methods inherited from class org.apache.druid.query.BaseQuery

calculateDuration, checkInterrupted, computeOverriddenContext, computeOverridenContext, context, getContext, getDataSource, getDuration, getGranularity, getId, getIntervals, getQuerySegmentSpec, getResultOrdering, getRunner, getSubQueryId, getTimezone, withId, withSqlQueryId, withSubQueryId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.druid.query.Query

getContextBoolean, getContextHumanReadableBytes, getContextValue, getMostSpecificId, getResultRowSignature, getSingleInterval, getSqlQueryId, mayCollapseQueryDataSource, withDefaultSubQueryId, withLane, withPriority

Field Details

TOPN

public static final String TOPN

See Also:

• Constant Field Values

Constructor Details

TopNQuery

public TopNQuery(DataSource dataSource,
 VirtualColumns virtualColumns,
 DimensionSpec dimensionSpec,
 TopNMetricSpec topNMetricSpec,
 int threshold,
 QuerySegmentSpec querySegmentSpec,
 DimFilter dimFilter,
 Granularity granularity,
 List<AggregatorFactory> aggregatorSpecs,
 List<PostAggregator> postAggregatorSpecs,
 Map<String,Object> context)

Method Details

hasFilters

public boolean hasFilters()

getFilter

public DimFilter getFilter()

getType

public String getType()

getVirtualColumns

public VirtualColumns getVirtualColumns()

getDimensionSpec

public DimensionSpec getDimensionSpec()

getTopNMetricSpec

public TopNMetricSpec getTopNMetricSpec()

getThreshold

public int getThreshold()

getDimensionsFilter

@Nullable
public DimFilter getDimensionsFilter()

getAggregatorSpecs

public List<AggregatorFactory> getAggregatorSpecs()

getPostAggregatorSpecs

public List<PostAggregator> getPostAggregatorSpecs()

getRequiredColumns

@Nullable
public Set<String> getRequiredColumns()

Description copied from interface: Query

Returns the set of columns that this query will need to access out of its datasource.

This method does not "look into" what the datasource itself is doing. For example, if a query is built on a QueryDataSource, this method will not return the columns used by that subquery. As another example, if a query is built on a JoinDataSource, this method will not return the columns from the underlying datasources that are used by the join condition, unless those columns are also used by this query in other ways.

Returns null if the set of required columns cannot be known ahead of time.

initTopNAlgorithmSelector

public void initTopNAlgorithmSelector(TopNAlgorithmSelector selector)

getResultRowSignature

public RowSignature getResultRowSignature(RowSignature.Finalization finalization)

withQuerySegmentSpec

public TopNQuery withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec)

Description copied from interface: Query

Returns a new query, identical to this one, but with a different associated QuerySegmentSpec.

This often changes the behavior of Query.getRunner(QuerySegmentWalker), since most queries inherit that method from BaseQuery, which implements it by calling QuerySegmentSpec.lookup(org.apache.druid.query.Query<T>, org.apache.druid.query.QuerySegmentWalker).

withDimensionSpec

public TopNQuery withDimensionSpec(DimensionSpec spec)

withAggregatorSpecs

public TopNQuery withAggregatorSpecs(List<AggregatorFactory> aggregatorSpecs)

withPostAggregatorSpecs

public TopNQuery withPostAggregatorSpecs(List<PostAggregator> postAggs)

withDataSource

public Query<Result<TopNResultValue>> withDataSource(DataSource dataSource)

optimizeForSegment

public Query<Result<TopNResultValue>> optimizeForSegment(PerSegmentQueryOptimizationContext optimizationContext)

withThreshold

public TopNQuery withThreshold(int threshold)

withOverriddenContext

public TopNQuery withOverriddenContext(Map<String,Object> contextOverrides)

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class BaseQuery<Result<TopNResultValue>>

hashCode

public int hashCode()

Overrides:

hashCode in class BaseQuery<Result<TopNResultValue>>